Disturbance in the protein landscape of cochlear perilymph in an Alzheimer's disease mouse model.

Hearing loss is a pivotal risk factor for dementia. It has recently emerged that a disruption in the intercommunication between the cochlea and brain is a key process in the initiation and progression of this disease. However, whether the cochlear properties can be influenced by pathological signals associated with dementia remains unclear. In this study, using a mouse model of Alzheimer's disease (AD), we investigated the impacts of the AD-like amyloid ß (Aß) pathology in the brain on the cochlea. Despite little detectable change in the age-related shift of the hearing threshold, we observed quantitative and qualitative alterations in the protein profile in perilymph, an extracellular fluid that fills the path of sound waves in the cochlea. Our findings highlight the potential contribution of Aß pathology in the brain to the disturbance of cochlear homeostasis.

Visualization of Reissner's membrane in the mouse inner ear using highly sensitive magnetic resonance imaging analysis.

Although research on hearing loss, including the identification of causative genes, has become increasingly active, the pathogenic mechanism of hearing loss remains unclear. One of the reasons for this is that the structure of the inner ear of mice, which is commonly used as a genetically modified animal model, is too small and complex, making it difficult to accurately capture abnormalities and dynamic changes in vivo. Especially, Reissner's membrane is a very important structure that separates the perilymph and endolymph of the inner ear. This malformation or damage induces abnormalities in hearing and balance. Until now, imaging analyses, such as magnetic resonance imaging (MRI) and computed tomography, are performed to investigate the inner ear structure in vivo; however, it has been difficult to analyze the small inner ear structure of mice owing to resolution. Therefore, there is an urgent need to develop an image analysis method that can accurately capture the structure of the inner ear of mice including Reissner's membrane, both dynamically and statically. This study aimed to investigate whether it is possible to accurately capture the structure (e.g., Reissner's membrane) and abnormalities of the inner ear of mice using an 11.7 T MRI. By combining two types of MRI methods, in vivo and ex vivo, we succeeded for the first time in capturing the fine structure of the normal mouse inner ear, such as the Reissner's membrane, and inflammatory lesions of otitis media mouse models in detail and accurately. In the future, we believe that understanding the state of Reissner's membrane during living conditions will greatly contribute to the development of research on inner ear issues, such as hearing loss.

Vertical infantile nystagmus: Explanation of why the direction of nystagmus is vertical.

This case report presents a rare case of infantile nystagmus syndrome (INS) in which the direction of infantile nystagmus (IN) was vertical. A 66-year-old woman was referred to our department for investigation of abnormal eye movements. She showed a disordered field of view with a homonymous hemianopia in the lower left quadrant and vertical gaze-evoked nystagmus, but there were no other abnormal neurological findings. She did not complain of an oscillopsia. Imaging revealed that the cause of hemianopia was atrophy and low cerebral blood flow in the right occipital lobe. The vertical nystagmus became strong when attempting to fixate to stationary targets. A reversed optokinetic nystagmus response was observed in the vertical optokinetic nystagmus test. From these eye movements, we diagnosed her nystagmus as vertical IN. Patients with INS see everything by saccades. IN consists of the alternate appearance of saccades and preceding slow eye movements. For these eye movements, a wide visual field is necessary. In this case, vertical IN was caused by the wider vertical than horizontal visual field resulting from homonymous hemianopia. Therefore, the direction of IN is horizontal in most patients with INS because their horizontal visual field is the widest field.

A mouse model of autoimmune inner ear disease without endolymphatic hydrops.

Autoimmune inner ear disease (AIED) is an organ-specific disease characterized by irreversible, prolonged, and progressive hearing and equilibrium dysfunctions. The primary symptoms of AIED include asymmetric sensorineural hearing loss accompanied by vertigo, aural fullness, and tinnitus. AIED is divided into primary and secondary types. Research has been conducted using animal models of rheumatoid arthritis (RA), a cause of secondary AIED. However, current models are insufficient to accurately analyze vestibular function, and the mechanism underlying the onset of AIED has not yet been fully elucidated. Elucidation of the mechanism of AIED onset is urgently needed to develop effective treatments. In the present study, we analyzed the pathogenesis of vertigo in autoimmune diseases using a mouse model of type II collagen-induced RA. Auditory brain stem response analysis demonstrated that the RA mouse models exhibited hearing loss, which is the primary symptom of AIED. In addition, our vestibulo-oculomotor reflex analysis, which is an excellent vestibular function test, accurately captured vertigo symptoms in the RA mouse models. Moreover, our results revealed that the cause of hearing loss and vestibular dysfunction was not endolymphatic hydrops, but rather structural destruction of the organ of Corti and the lateral semicircular canal ampulla due to an autoimmune reaction against type II collagen. Overall, we were able to establish a mouse model of AIED without endolymphatic hydrops. Our findings will help elucidate the mechanisms of hearing loss and vertigo associated with AIED and facilitate the development of new therapeutic methods.

Validation and comparison of prognostic scoring systems in patients with head and neck squamous cell carcinoma treated with nivolumab.

OBJECTIVE: Several scoring systems have been developed to predict prognosis in patients with refractory cancer. We aimed to validate eight scoring systems and determine the best method for predicting the prognosis of head and neck squamous cell carcinoma treated with nivolumab. METHODS: This multicentre retrospective study involved 154 patients with recurrent and/or metastatic head and neck squamous cell carcinoma treated with nivolumab between 2017 and 2020. Oncological outcomes were assessed according to the scoring systems, including MD Anderson Cancer Center + neutrophil-to-lymphocyte ratio and Hammersmith scores. Objective response, overall survival and progression-free survival were evaluated using logistic regression and Cox proportional hazards analyses. Receiver operating curve analysis was used to calculate the area under the curve and estimate the efficacy of each score. RESULTS: No significant associations were found between the responses and any score. Seven of the eight scoring systems were associated with disease control (odds ratio, 0.26-0.70). Amongst the eight scoring systems, MD Anderson Cancer Center + neutrophil-to-lymphocyte ratio showed the highest area under the curve for predicting response and disease control. Seven scoring systems were prognostic factors for progression-free survival (hazard ratio, 1.22-1.95). All eight scoring systems were prognostic factors for overall survival (hazard ratio, 1.62-3.83). According to the time-dependent receiver operating characteristics analysis for overall survival, the Hammersmith scoring system had the best predictive ability at 3 months, and the MD Anderson Cancer Center + neutrophil-to-lymphocyte ratio scoring system had the highest area under the curve between 6 and 24 months. CONCLUSIONS: MD Anderson Cancer Center + neutrophil-to-lymphocyte ratio and Hammersmith scoring systems were better predictors of prognosis in patients with head and neck squamous cell carcinoma treated with nivolumab.

Sema6D forward signaling impairs T cell activation and proliferation in head and neck cancer.

Immune checkpoint inhibitors (ICIs) are indicated for a diverse range of cancer types, and characterizing the tumor immune microenvironment is critical for optimizing therapeutic strategies, including ICIs. T cell infiltration and activation status in the tumor microenvironment greatly affects the efficacy of ICIs. Here, we show that semaphorin 6D (Sema6D) forward signaling, which is reportedly involved in coordinating the orientation of cell development and migration as a guidance factor, impaired the infiltration and activation of tumor-specific CD8+ T cells in murine oral tumors. Sema6D expressed by nonhematopoietic cells was responsible for this phenotype. Plexin-A4, a receptor for Sema6D, inhibited T cell infiltration and partially suppressed CD8+ T cell activation and proliferation induced by Sema6D stimulation. Moreover, mouse oral tumors, which are resistant to PD-1-blocking treatment in wild-type mice, showed a response to the treatment in Sema6d-KO mice. Finally, analyses of public data sets of human head and neck squamous cell carcinoma, pan-cancer cohorts, and a retrospective cohort study showed that SEMA6D was mainly expressed by nonhematopoietic cells such as cancer cells, and SEMA6D expression was significantly negatively correlated with CD8A, PDCD1, IFNG, and GZMB expression. Thus, targeting Sema6D forward signaling is a promising option for increasing ICI efficacy.

Association of circulating tumor HPV16DNA levels and quantitative PET parameters in patients with HPV-positive head and neck squamous cell carcinoma.

Circulating tumor DNA (ctDNA), which circulates in the blood after being shed from cancer cells in the body, has recently gained attention as an excellent tumor marker. The purpose of this study was to evaluate whether ct human papillomavirus (HPV) 16 DNA (ctHPV16DNA) levels were associated with quantitative PET parameters in patients with HPV-positive head and neck (HN) squamous cell carcinoma (SCC). Fifty patients with oropharyngeal SCC (OPSCC) and 5 with SCC of unknown primary (SCCUP) before treatment were included. They all underwent blood sampling to test ctHPV16DNA levels and FDG PET-CT examinations. Quantitative PET parameters included SUVmax, metabolic tumor volume (MTV), MTV of whole-body lesions (wbMTV), and 56 texture features. ctHPV16DNA levels were compared to texture features of primary tumors in OPSCC patients (Group A) or the largest primary or metastatic lymph node lesions in OPSCC and SCCUP patients (Group B) and to other PET parameters. Spearman rank correlation test and multiple regression analysis were used to confirm the associations between ctHPV16DNA levels and PET parameters. ctHPV16DNA levels moderately correlated with wbMTV, but not with SUVmax or MTV in Groups A and B. ctHPV16DNA levels exhibited a weak negative correlation with low gray-level zone emphasis in Groups A and B. Multiple regression analysis revealed that wbMTV and high gray-level zone emphasis were the significant factors for ctHPV16DNA levels in Group B. These results were not observed in Group A. This study demonstrated that ctHPV16DNA levels correlated with the whole-body tumor burden and tumor heterogeneity visualized on FDG PET-CT in patients with HPV-positive HNSCC.

Circulating Plasma Exosomal PD-L1 Predicts Prognosis of Head and Neck Squamous Cell Carcinoma After Radiation Therapy.

Purpose: Radiation therapy is widely used to treat head and neck squamous cell carcinoma (HNSCC). This study evaluated the association between circulating plasma programmed death-ligand 1 (PD-L1) and the outcomes of patients with HNSCC after radiation therapy. Methods and Materials: In this retrospective observational study, plasma samples of 76 patients with HNSCC who underwent radiation therapy from June 2019 to August 2021 were analyzed. These plasma samples were obtained before radiation therapy. The median follow-up was 32.5 months. Total and exosomal PD-L1 was measured by enzyme-linked immunosorbent assay and retrospectively analyzed for association with overall survival (OS), progression-free survival (PFS), and local control (LC). Prognostic factors among patients' characteristics and circulating PD-L1 in plasma were evaluated by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses. Results: The median concentration of total PD-L1 in plasma was 115.1 pg/mL (95% CI, 114.7-137.9 pg/mL), and the median concentration of exosomal PD-L1 was 2.8 pg/mL (95% CI, 6.0-13.0 pg/mL). Univariate and multivariate analyses showed exosomal PD-L1 as a prognostic factor for PFS and LC. Patients with high exosomal PD-L1 in plasma had poor PFS and LC compared with those with low exosomal PD-L1, indicating that 1-year PFS was 79.2% versus 33.3% (P < .001) and 1-year LC was 87.3% versus 50.0% (P < .001) in patients with high and low exosomal PD-L1, respectively. However, exosomal PD-L1 in plasma had no significant effect on OS. Total PD-L1 in plasma did not correlate with PFS, LC, and OS. Conclusions: The pretreatment circulating exosomal PD-L1 in plasma of patients with HNSCC was a prognostic factor after radiation therapy.

Understanding hereditary hemorrhagic telangiectasia: From genetic anomalies to systemic manifestations, quality of life, and epistaxis management-Exploring the otolaryngologist's integral role.

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Rendu-Weber syndrome, is a rare autosomal dominant disorder characterized by vascular malformations. This comprehensive review aimed to provide an overview and summarize various aspects of HHT, including the genetic abnormalities, complications associated with visceral arteriovenous malformations (AVMs), prognosis of HHT, quality of life (QOL), and treatment of epistaxis. In addition, this review highlights the challenges in diagnosing HHT and emphasizes the critical role of otolaryngologists in the early detection of HHT. Otolaryngologists can refer patients with refractory epistaxis for AVM screening to expedite intervention. Mutation of the genes involved in the transforming growth factor-ß signaling pathway leads to the incidence of HHT, resulting in the formation of abnormal blood vessel formation. These vascular malformations commonly manifest as telangiectasia on the skin and mucous membranes; however, epistaxis remains the hallmark symptom of HHT. The impact of HHT goes beyond the visible symptoms and often includes the formation of life-threatening visceral AVMs in the lungs, liver, and brain. The prognosis of patients with HHT is closely related to the development of these complications, necessitating timely diagnosis and intervention. Refractory epistaxis diminishes the QOL of patients with HHT. The management of epistaxis ranges from conservative measures to advanced interventions such as prevention, conservative treatments, ablation, surgical procedures, and the administration of anti-angiogenic agents. However, effective management requires a multidisciplinary approach. The diagnosis of HHT remains challenging due to its variable presentation and lack of awareness among physicians. This review highlights the importance of reducing the duration between symptom onset and diagnosis. Otolaryngologists who are experienced in the management of refractory epistaxis can aid in identifying potential cases of HHT. They can facilitate the initiation of screening for visceral AVMs via prompt recognition of the signs and symptoms of HHT, contributing to improved patient outcomes. Early detection and intervention through screening can extend the life expectancy of patients with HHT to levels comparable with that of the general population. In conclusion, this review provides insight into various aspects of HHT and emphasizes the importance of timely diagnosis and intervention in the mitigation of the potentially life-threatening complications associated with this disorder. Otolaryngologists play a critical role in this process, serving as gatekeepers to the identification of cases of HHT and implementation of appropriate screening and management pathways, thereby improving the life expectancy and QOL of patients.

The Minimal Important Difference of Acoustic Voice Quality Index in the Treatment of Voice Disorders.

OBJECTIVES: The acoustic voice quality index (AVQI) is a reliable tool that objectively assesses dysphonia levels using six acoustic parameters. Despite its high criterion-related concurrent validity, diagnostic accuracy, and minimal detectable change derived from test-retest reliability, the minimal important difference (MID) of the AVQI has not been tested before. This study aimed to estimate the MIDs of AVQI for improvement audibly perceived by clinicians and self-reported improvement by patients. METHODS: A retrospective study was conducted on 110 patients who received treatment for voice disorders. Patients completed AVQI and Voice Handicap Index-10 (VHI-10) questionnaires before and after the therapy. The MIDs of the AVQI were estimated using the anchor of either auditory-perceptual judgment of total dysphonia levels by clinicians or the VHI-10 questionnaire by patients. A distribution-based approach was also used to complement the results. RESULTS: First, using the auditory-perceptual anchor, a decrease of 0.95 in the AVQI was estimated as the MID for clinicians' perception, as a result of the receiver operating curve. Then, using the patient-reported anchor, an improvement of 1.36 in the AVQI was estimated as the MID for patients' voice-related disability. The distribution-based approach also ensured the anchor-based results of both the MIDs. CONCLUSIONS: The AVQI is a reliable and valid tool for evaluating voice quality, and a 0.95 decrease in the AVQI represents a meaningful improvement for clinicians' perception, whereas a 1.36 decrease in the AVQI influences patients' self-reported disability. This study contributes to understanding the minimal change necessary for clinicians to make informed decisions and ensure patient satisfaction. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2805-2811, 2024.

Prognostic significance of nutritional indices in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors.

BACKGROUND: Although patients with head and neck squamous cell cancer (HNSCC) often show malnutrition, its effects on immune checkpoint inhibitor (ICI) treatment outcomes in these patients are unclear. OBJECTIVES: To investigate the prognostic influence of nutritional indices in patients with HNSCC treated with ICIs and determine the optimal indices. METHODS: This retrospective study included 106 patients with HNSCC treated with ICIs between 2017 and 2022. The prognostic influences of body mass index (BMI), geriatric nutritional risk index (GNRI), and prognostic nutritional index (PNI) on overall survival (OS) and progression-free survival (PFS) were analysed using the Kaplan-Meier method and Cox-regression models. RESULTS: The 1-year PFS rates in the groups with high and low BMI, GNRI, and PNI were, respectively, 24.2% and 28.4% (p = .731), 29.7% and 14.4% (p = .024), and 30.3% and 13.9% (p = .015). PNI was an independent prognostic factor for both PFS (hazard ratio (HR) = 1.89; 95% confidence interval (CI), 1.08-3.29) and OS (HR = 3.26; 95% CI, 1.66-6.40). CONCLUSIONS: PNI can predict ICI outcomes and should be assessed when ICI treatment is considered.

Validation of Subharmonics Quantification Using Two-Stage Cepstral Analysis.

OBJECTIVES: Hoarseness is primarily perceived as breathiness or roughness. Despite the various tools that quantitatively assess hoarseness, roughness has been difficult to quantify because of its complex acoustic structure, such as subharmonics. The parameter obtained from the two-stage cepstral analysis is promising for evaluating roughness. Thus, this study aimed to improve the accuracy of the parameter using a customized pitch setting and investigate the relationship between roughness and subharmonics. STUDY DESIGN: The design is a retrospective study. METHODS: Two-stage cepstral analysis was used to analyze the voice recordings of 455 participants, speech impaired and normal controls, using the Analysis of Dysphonia in Speech and Voice and Praat software. For validation, the ground truth of subharmonics was visually quantified using a narrowband spectrogram. The reliability and validity of the two-stage cepstral analysis and subharmonics measures on spectrograms were evaluated. RESULTS: The two-stage cepstral analysis showed a very strong correlation (r = 0.963) between the two software programs. Intra- and inter-rater reliability of the subharmonics measures on spectrograms were also good. Two-stage cepstral analysis showed that even with customized pitch settings, the diagnostic systems and correlations for perceptual roughness and subharmonics were weak to moderate. The subharmonics measures on spectrograms showed a strong correlation with roughness and moderate diagnostic accuracy of subharmonics. CONCLUSIONS: The two-stage cepstral analysis showed some improvement in diagnostic accuracy and correlation with customized pitch settings, but it did not sufficiently detect subharmonics or roughness. The analysis using subharmonics measures on spectrograms proved the high correlation between subharmonics and roughness, indicating that developing acoustic analysis parameters that sufficiently detect subharmonics is necessary.

An Unusual Case of Eosinophilic Chronic Rhinosinusitis With Concurrent Eosinophilic Otitis Media: Limited Responsiveness to Multiple Antibody Therapies and Subsequent Cochlear Implantation.

Eosinophilic chronic rhinosinusitis (ECRS) and eosinophilic otitis media (EOM) are debilitating inflammatory conditions that affect the paranasal sinuses and middle ear, respectively, and are characterized by eosinophilic infiltration. This study describes a rare and intricate case of a 65-year-old male patient concurrently afflicted with ECRS, EOM, and bronchial asthma. Despite the systematic administration of corticosteroids and various antibody drugs, the patient's condition remained unimproved, necessitating a cochlear implant for EOM, which is seldom an aggressive intervention. The patient had a history of symptoms dating back to 2005, with notable exacerbations and treatment resistance over the years. Multiple antibody drugs, including anti-IgE, anti-IL-5, and anti-IL-4α antibodies, failed to ameliorate the patient's condition, presenting a significant clinical challenge. Pathological examination revealed marked eosinophilic infiltration and severe fibrosis, suggesting a possible mechanism underlying the poor response to antibody therapy. Cochlear implantation significantly enhanced the patient's communicative abilities. This case highlights the limitations of the current antibody drugs in managing severely intertwined cases of ECRS, EOM, and bronchial asthma, highlighting the need for novel therapeutic strategies. This case also propounds cochlear implantation as an efficacious intervention for refractory EOM with severe sensorineural hearing impairment, extending the spectrum of treatment modalities for such challenging scenarios. This singular case contributes to the growing body of evidence regarding the management of ECRS and EOM, especially against the backdrop of treatment resistance, and can aid clinicians in identifying and navigating similar complex cases in clinical practice.

Microscopic Residual Disease After Nasal Squamous Cell Carcinoma Not Visualized on FDG PET-CT: A Case Report.

Nasal squamous cell carcinoma (SCC) is rare and aggressive. It often requires combination treatment. Precise post-treatment disease assessment is vital for determining the subsequent management and prognosis. We present the intriguing case of a 52-year-old man with T4bN0M0 stage IVB SCC. Post-treatment fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) findings indicated a complete response; however, microscopic remnants of the cancer were detected during endoscopic sinus surgery. This report underscores the limitations of post-treatment assessment using FDG PET-CT and outpatient endoscopy alone due to these modalities' potential inability to detect microscopic residual disease. Endoscopic sinus surgery should be incorporated into routine post-treatment assessments of nasal SCC to improve disease detection and guide further treatment. Further large-scale studies are required to confirm these findings.

Analysis of gut microbiome, host genetics, and plasma metabolites reveals gut microbiome-host interactions in the Japanese population.

Interaction between the gut microbiome and host plays a key role in human health. Here, we perform a metagenome shotgun-sequencing-based analysis of Japanese participants to reveal associations between the gut microbiome, host genetics, and plasma metabolome. A genome-wide association study (GWAS) for microbial species (n = 524) identifies associations between the PDE1C gene locus and Bacteroides intestinalis and between TGIF2 and TGIF2-RAB5IF gene loci and Bacteroides acidifiaciens. In a microbial gene ortholog GWAS, agaE and agaS, which are related to the metabolism of carbohydrates forming the blood group A antigen, are associated with blood group A in a manner depending on the secretor status determined by the East Asian-specific FUT2 variant. A microbiome-metabolome association analysis (n = 261) identifies associations between bile acids and microbial features such as bile acid metabolism gene orthologs including bai and 7ß-hydroxysteroid dehydrogenase. Our publicly available data will be a useful resource for understanding gut microbiome-host interactions in an underrepresented population.

L-Glutamine and Survival of Patients with Locally Advanced Head and Neck Cancer Receiving Chemoradiotherapy.

We previously reported that L-glutamine reduces the severity of mucositis caused by chemoradiotherapy in patients with head and neck cancer. However, the impact of glutamine on the anti-tumor effect of chemoradiotherapy remains controversial. This study, which included 40 patients, investigated whether L-glutamine influences survival. Radiation therapy (total: 66 or 70 Gy), cisplatin, and docetaxel were co-administered for a period of 6 weeks. Patients were randomly assigned to receive either glutamine (glutamine group, n = 20) or placebo (placebo group, n = 20) during the entire course of chemoradiotherapy. We compared the overall survival and progression-free survival rates between the two groups. At 5-year follow-up, 16 (80%) and 13 (72%) patients in the glutamine and placebo groups, respectively, survived (with no significant difference in overall survival [glutamine group: 55.2 ± 12.7 months vs. placebo group: 48.3 ± 21.3 months]). A total of 14 (70%) and 12 (67%) patients in the glutamine and placebo groups, respectively, did not experience disease progression (with no significant difference in progression-free survival [glutamine group: 46.7 ± 19.5 months vs. placebo group: 43.6 ± 25.2 months]). These findings indicate that L-glutamine does not influence the survival of patients with locally advanced head and neck cancer receiving chemoradiotherapy.

Differential dependence on microbiota of IL-23/IL-22-dependent gene expression between the small- and large-intestinal epithelia.

In the intestine, interleukin (IL)-23 and IL-22 from immune cells in the lamina propria contribute to maintenance of the gut epithelial barrier through the induction of antimicrobial production and the promotion of epithelial cell proliferation. Several previous studies suggested that some of the functions of the IL-23/IL-22 axis on intestinal epithelial cells are shared between the small and large intestines. However, the similarities and differences of the IL-23/IL-22 axis on epithelial cells between these two anatomical sites remain unclear. Here, we comprehensively analyzed the gene expression of intestinal epithelial cells in the ileum and colon of germ-free, Il23-/- , and Il22-/- mice by RNA-sequencing. We found that while the IL-23/IL-22 axis is largely dependent on gut microbiota in the small intestine, it is much less dependent on it in the large intestine. In addition, the negative regulation of lipid metabolism in the epithelial cells by IL-23 and IL-22 in the small intestine was revealed, whereas the positive regulation of epithelial cell proliferation by IL-23 and IL-22 in the large intestine was highlighted. These findings shed light on the intestinal site-specific role of the IL-23/IL-22 axis in maintaining the physiological functions of intestinal epithelial cells.

Paranasal Schwannomas: A Comprehensive Study of 2 Cases.

Paranasal sinus tumors are a heterogeneous group of neoplasms (with paranasal schwannomas being a rare subtype) that are often present with non-specific symptoms, such as nasal obstruction and epistaxis. Thus, early diagnosis is crucial for optimal management. This study presents 2 cases of paranasal schwannomas, detailing their clinical presentation, diagnostic methods, and treatment approaches. Both patients underwent endoscopic sinus surgery with successful tumor excision and had no significant complications or recurrences during follow-up. Diagnosis was based on a combination of clinical examination, radiological imaging (computed tomography and magnetic resonance imaging), and histopathological confirmation with immunohistochemical staining. Treatment consisted primarily of endonasal resection, with consideration of frontal craniotomy if necessary. This study aims to contribute to the understanding of paranasal schwannomas and emphasizes the importance of early detection and treatment to improve patient outcomes.

A Rare Case of Pseudo-Malignant Paranasal Extranodal Rosai-Dorfman Disease.

Rosai-Dorfman disease is a very rare disease characterized by histiocytic accumulation in the head and neck region and lymph node enlargement. We report a rare pseudo-malignant paranasal extranodal Rosai-Dorfman disease. A 69-year-old-man presented nasal bleeding and nasal obstruction. Paranasal mass was detected in the left nasal cavity and computed tomography (CT) findings are the sphenoid sinus, maxillary sinus, and ethmoid sinus were involved with inconstant bone thickening, however, no bone destruction was detected. Magnetic resonance imaging scans show iso-intensity signal in T1-weighed image and T2-weighed image. Positron emission tomography/CT fluorodeoxyglucose (FDG) uptake in posterior ethmoid sinus and sphenoid sinus, bilateral cervical lymph node, clavicle, and sternum. Based on the above results, we considered malignant lymphoma and performed a biopsy. After pathological examination, a diagnosis of Rosai-Dorfman disease was established.

Single-cell transcriptomics of human cholesteatoma identifies an activin A-producing osteoclastogenic fibroblast subset inducing bone destruction.

Cholesteatoma, which potentially results from tympanic membrane retraction, is characterized by intractable local bone erosion and subsequent hearing loss and brain abscess formation. However, the pathophysiological mechanisms underlying bone destruction remain elusive. Here, we performed a single-cell RNA sequencing analysis on human cholesteatoma samples and identify a pathogenic fibroblast subset characterized by abundant expression of inhibin ßA. We demonstrate that activin A, a homodimer of inhibin ßA, promotes osteoclast differentiation. Furthermore, the deletion of inhibin ßA /activin A in these fibroblasts results in decreased osteoclast differentiation in a murine model of cholesteatoma. Moreover, follistatin, an antagonist of activin A, reduces osteoclastogenesis and resultant bone erosion in cholesteatoma. Collectively, these findings indicate that unique activin A-producing fibroblasts present in human cholesteatoma tissues are accountable for bone destruction via the induction of local osteoclastogenesis, suggesting a potential therapeutic target.